Perforation cleaner



March 1939- Y J. P. BLACK ET AL 2,151,416

PERFORATION CLEANER Filed May 3, 1938 A axmeo 6. 57205554 Y Patented Mar. '21, 1939 UNITED STATES 2,151,416 PERFORATION CLEANER Julian P. Black, Los Angeles, and Howard C. Stroebel, Whittier, Calif.

Application May a, 1938, Serial No. 205,746

7 Claims.

This invention relates to a perforation cleaner designed for cleaning the perforations in liners of oil wells and the like, although it may be used for analogous purposes.

In oil wells there -is generally positioned a production liner at the bottom of the well casing which extends into the producing zone or formation. These liners are perforated or slotted with small perforations or slots which permit the oil 10 to enter but which are designed to keep out sand and portions of the formation. It frequently occurs, however, that these perforations or slots become clogged with the result that ingress to the liner is materially retarded. It has been 5 proposed to clean such perforations by means of a suitable wire brush. However, difficulties are experienced with the conventional form of wire brush in that the wire bristles become permanently bent when the brush is being lowered into 20 the well. Consequently, when the bristles are thus damaged when the brush reaches the perforations in the liner it is not in a suitable condition to effectively clean the' perforations or slots therein. It is an object of the present invention to provide a perforation cleaner having wire bristles thereon which extend outwardly from the body of the cleaner and which are characterized by the fact that they are more readily bendable adjacent the body than outwardly therefrom. Consequently, during the lowering of the cleaner into the well, if the bristles encounter any obstruction or engage .the walls of the casing, the outwardly extending portions may bend bodily 35 with respect to the body of the perforation cleaner without becoming permanently bent. In this way, when the perforation cleaner reaches the liner the bristles will be returned automatically to their initial positions so as to be effective in cleaning the perforations or slots.

Another object of the invention is to provide a perforation cleaner generally in the form of a cylindrical wire brush and which is provided with suitable centering means for. maintaining the 45 perforation cleaner centrally of the liner while the perforations or slots therein are being cleaned.

Another object of the invention is to provide a novel form of bristle construction for wire brushes, perforation cleaners, and the like which is of relatively simple construction and which may be easily and quickly manufactured and which is capable of being easily and quickly mounted on the body of the perforation cleaner. 55 With the foregoing and other objects in view,

which will be made manifest in the following detailed description and specifically pointed out in the appended claims, reference is had to the accompanying drawing for an illustrative embodiment of the invention, wherein: 5

Figure l is a view in-side elevation of the improved perforation cleaner;

Fig. 2 is a horizontal section taken substantially upon the line 2-2 upon Fig. 1;

Fig. 3 is a view in side elevation of one of the 10 outer wire bristles of the improved perforation cleaner; and

Fig. 4 is a similar view to Fig. 3, illustrating one of the inner wire bristles.

Referring to the accompanying drawing wherein similar reference characters designate similar parts throughout, the improved perforation cleaner comprises a suitable body in preferably formed of a section of heavy walled tubing or pipe. At the bottom of the body there may be a suitable bullnose ll suitably shaped to prevent the construction from becoming caught or hung in the casing or liner as it is being lowered into the well. The top of the body is provided with a suitable wrench square I2 and a threaded pin l3 by which it may be attached to a set of jars (not shown) and to a sinker bar or one or more sections of pipe (not shown) which will supply the required weight to force the construction downwardly into the liner. Adjacent the top and bottom of the body there are a plurality of outwardly bowed springs l4 constituting centering springs designed to engage with the interior surface of the liner to hold the body if] centrally thereof during the cleaning operations; Body i0 is equipped with a multiplicity of outwardly extending radial wire bristles l5. In the perferred form of construction these bristles are arranged in helical rows extending around the body as shown, although any other preferred arrangement may be adopted.

In the preferred form of construction each bristle is made of inner and outer wires, the outer wire beingillustrated in Fig. 3 and the inner wire being illustrated in Fig. 4. The outer wire l6 has a radial portion l1 at the base of which there are several coil-like convolutions l8 forming a type of coil spring at the base. The end of the wire -,I 9 is bent laterally from the lowermost convolution forming a suitable tail. The 5 inner wire generally designated at 20 is similarly constructed with the exception that its coil-like convolutions 2| are formed on a smaller diameter than the convolutions l8. This" enables the convolutions 2| to be teiescoped inside of convolu- 21bristle comprises radially extending portions l1 be made of a single and-'22.;on the two wires, each radial portion being iconnected at its base to several coil-like convolutions which, in turn, are connected to the laterally extending tails l9 and 23. When the two wires are assembled or nested together they, have their spring-like coils disposed in-recesses, 24 drilled into the exterior surface of body in. The laterally extending tails extend laterally through the body in small drilled holes 25 and are secured therein by means of threaded plugs 25.

The operation and advantages of the improved perforation cleaner are as follows: As the device is being lowered into the well, if the radial extending portions l1 and 22 of the bristles should encounter some obstruction or should engage the walls of the casing or of the liner, the radially extending portions will not bend nor become permanently bent from their radial positions. Instead, the radial portions will remain straight, all bending taking place in the coils l8 and M. In other words, should the radial portions l1 and 22 encounter some obstruction tending to bend them upwardly, these radial portions will be bent bodily in an upward direction with most of the bending taking place in the springlike coils l8 and 2|.

When the bristles pass the obstruction or are released, the eifect of the spring-like coils is to instantly return the radially extending portions to their initial radial positions. In this way,.the outwardly extending portions of the bristles will be maintained in proper condition at the time that the level of the perforations or slots in the liner is reached. When the perforated portion of the liner is reached the perforations are cleaned by merely reciprocating the perforation cleaner up and down inthe liner. The customary practice is to start at the bottom of the liner and during the reciprocation gradually work upwardly. After the liner has been cleaned, the perforation cleaner is bodily withdrawn.

In use of the present type of construction,we have found that we have been able to increase the production of oil wells having badly clogged perforations in their liners, from between 25 and 50%.

It is not essential that each bristle be made up of two wires having their coils nested one within the other. If desired, each bristle may wire having its coil recessed in the body. We prefer to employ the double wire construction for the reason that the radially extending portions I1 and 22 being positioned side by side, mutually contribute to each others stiffness. At the same time each of the radial portions is more readily bendable in the spring-like coils in the recesses in the body I0. It will be noted that the convolutions of the coils are arranged in planes transverse with respect to the radially or outwardly extending portions of the bristles so that the axes of the convolutions are approximately parallel to their respective radial or bristle portions.

During the cleaning operation when the perforation cleaner is reciprocated, the overall diameter of the perforation cleaner being somewhat in excess of the interior diameter of the liner, the radial portions of the bristles at the ends of the reciprocating strokes enter the perforations or slots in the liner and poke outwardly any clogging material thus cleaning the perforations.

Various changes may be made in the details of construction without departing from the spirit or scope of the invention as defined by the appended claims.

We claim:

1. A perforation cleaner comprising a body having a plurality of outwardly extending wire bristles secured thereto, said bristles having a plurality of convolutions formed therein adjacent the body arranged in planes transverse to the lengths of the bristles rendering the bristles more readily bendable adjacent the body than outwardly therefrom.

2. A perforation cleaner comprising a body, there being recesses formed in the exterior surface of the body, and wire bristles, each having coil-like convolutions disposed in the recesses, the axes of the convolutions being substantially parallel to the lengths of the bristles, thereby rendering the bristles more readily bendable adjacent the body than outwardly therefrom.

3. A perforation cleaner comprising a. body, there being recesses formed in the exterior surface of the body, and wire bristles, each having coil-like convolutions disposed in the recesses,

rendering the bristles more readily bendable adjacent the body than outwardly therefrom, each bristle having a tail and means for securing the tails in the body.

4. A bristle for perforation cleaners and the which has an outwardly extending portion and each of which has adjacent its inner end a plurality of coil-like convolutions, the coil-like convolutions of one wire being disposed within the coil-like convolutions of the other wire.

7. A bristle for perforation cleaners and the like, comprising two sections of wire, each of which has an outwardly extending portion and each of which has adjacent its inner end a plurality of coil-like convolutions, the coil-like convolutions of one wire being disposed within the coil-like convolutions of the other wire, each wire having a laterally extending tail.

JULIAN P. BLACK. HOWARD C. STROEBEL.

perforation cleaners and the i like, comprising a section of wire having an outsection of wire having an outtil 

